BISCO MF1 Bun silicone is a lightweight cellular silicone foam cast into block form. This high quality material is designed for a wide range of cushioning applications such as passenger rail car seating. MF1 silicone’s proven durability and fire resistance means reliable comfort, longevity and safety. MF1 is available in three firmness ranges, allowing engineers to optimize seat designs and maximize passenger comfort while reducing weight and size.


  • Available in blocks up to 8 in. thick
  • Tested for a UL94 V-0 and HF-1 rating
  • Low compression set
  • Used most often as cushion foam in passenger rail car seating


  • Exceptional flame, smoke and toxicity (FST) resistance performance
  • Superior weather and UV resistance
  • Outperforms competitive cushion foams in durability
  • Ensures safety, long cushion life and lasting passenger comfort



Explore our calculators, conversion tools, technical papers and more.

  • BISCO® Product Properties Guide

    Filter BISCO® product information by various criteria, including property groups, product category or units, to find the best material for the application.

  • Application Design Tool

    Determine the best BISCO® silicone or PORON® polyurethane material for specific design application.

  • Compression Force Deflection Curve Tool

    Identify design-appropriate BISCO® silicone, PORON® polyurethane and ARLON® silicone materials using stress-strain data.

  • Impact Prediction Tool

    Select the best BISCO® silicone or PORON® polyurethane for energy absorbing applications using impact data.

  • Vibration Isolation Tool

    The Vibration Isolation Tool recommends the proper BISCO® silicone and PORON® polyurethane materials for your vibration mitigation applications.

  • BISCO® MF1® Rail Seat Cushion

    This tool will assist with the calculation of cushioning cost based on your entered criteria.

Need a Sample?

Samples can be requested through our online request system.


Elastomeric Material Solutions

Find local representatives for personalized support.